/*
 * Copyright (C) 2017 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.util.concurrent;

import static com.google.common.base.StandardSystemProperty.JAVA_CLASS_PATH;
import static com.google.common.base.StandardSystemProperty.PATH_SEPARATOR;

import com.google.common.base.Splitter;
import com.google.common.collect.ImmutableList;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;

// TODO(b/65488446): Make this a public API.

/**
 * Utility method to parse the system class path.
 */
final class ClassPathUtil
{
    private ClassPathUtil()
    {
    }

    /**
     * Returns the URLs in the class path specified by the {@code java.class.path} {@linkplain
     * System#getProperty system property}.
     */
    // TODO(b/65488446): Make this a public API.
    static URL[] parseJavaClassPath()
    {
        ImmutableList.Builder<URL> urls = ImmutableList.builder();
        for (String entry : Splitter.on(PATH_SEPARATOR.value()).split(JAVA_CLASS_PATH.value()))
        {
            try
            {
                try
                {
                    urls.add(new File(entry).toURI().toURL());
                }
                catch (SecurityException e)
                { // File.toURI checks to see if the file is a directory
                    urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
                }
            }
            catch (MalformedURLException e)
            {
                AssertionError error = new AssertionError("malformed class path entry: " + entry);
                error.initCause(e);
                throw error;
            }
        }
        return urls.build().toArray(new URL[0]);
    }

    /**
     * Returns the URLs in the class path.
     */
    static URL[] getClassPathUrls()
    {
        return ClassPathUtil.class.getClassLoader() instanceof URLClassLoader
                ? ((URLClassLoader) ClassPathUtil.class.getClassLoader()).getURLs()
                : parseJavaClassPath();
    }
}
